So I have a 2001 cavalier Z24 I have a CAI, ported TB and I just ordered a header. I also had a question will I gain any power by just adding the header to stock exhaust and if not will adding the header and a muffler add any power. And last but not least by just adding the header will MPG be any better as well as the sound through the stock muffler. So all this being said how much power am I making currently and how much should I make with the header.

Untuned...

Probably less than stock, due to its age.

untuned with intake and TB, probably 135-138whp.

Header will work much better with a full exhaust.



FU Tuning

just out of curiosity, how much would one gain with a tune with basic bolts ons like above? Just wondering how much of a difference a tune would make?


2000 Cavalier Z24 5spd - Intake, Dynomax muffler, Hawk Pads, Powerslot rotors, Sportlines/Koni reds, Neon Coil, MSD 8.5 Wires
2005 Mazda 3 GS Auto- Wifes car
2006 Cobalt SS/SC - Intake, 2.5" Exhaust, GMPP Brakes, Solid Mounts, Ported S/C - Sold
1991 GMC Sierra - Lifted on 38.5" Swampers, Too much to list off. For Sale

Id get the header... If you plan to stay mild bolt ons, run 2.25 piping back, otherwise run 2.5 pipe back.

Then put in secret cams... then you'll be up to the 140-150 whp range...

To clear the 170/180+ barrier, you need to do the motor's internals and get tuned... or apply some form of boost and get tuned (and i'd still do the internals for longevity)

I made 151whp with intake, header full exhaust, mounts, TB, secret cams. Factory tune.

I'm sure I would have been 160whp tuned (never got it on the dyno after I tuned it.

I'm sure with some port and polish work and maybe more cams and tune you will hit 170whp+ on factory motor.



FU Tuning